[FEATURE] higher antibot functionality

**What's needed and why ?**
Toggle antibot (e.g. captcha/javascript) automatically when theres an instant traffic spike, indicating pontential (D)DoS attack, so normally it doesn't hurt any SEO and does not annoy users, but helps to stay up during an attack/traffic spike
if such thing was implemented, it would've been awesome, and it generally does not sound hard to implement, since all the challenge code is already there

**Implementations ideas (optional)**
Its typically called a "sensor", and thats what the "top tier" security companies use to stop such attacks, e.g. cloudflare's anti ddos kicks in when theres a big traffic spike (requests/s), maybe bunkerized nginx could do something similar?
generally theres already a "project" existing that does that, but the way its published is kinda fishy, but theres a "sensor plugin" code for it that might help you understand anything https://github.com/ertugrulturan/vddos-sensor-plugin